ABSTRACT The Magnetic Resonance Imaging Core, located in the Sleep Imaging Center will act as a central facility to handle and process the large number of MRI's (in both humans and mice) and MR data analysis generated by Projects 1 and 3. The objectives of the Imaging Core are to: 1) transfer data from the MRI to the Sleep Imaging Center; 2) ensure proper data analysis of the MR images; 3) perform quantitative volumetric analysis of upper airway soft tissue and craniofacial structures and visceral abdominal fat in humans with MRI and quantify tongue fat with Dixon imaging; 4) perform quantitative volumetric analysis of upper airway soft tissue and visceral abdominal fat in mice with MRI and quantify tongue fat with Dixon imaging; 5) ensure quality control of the human and mice MR images; and 6) establish new automated computer analysis three- dimensional image analysis programs. The MR images will be electronically transferred to the Sleep Imaging Center via a Picture Archiving and Communication System (PACS). The image analysis will be performed in the Sleep Imaging Center where there are 6 workstations running AMIRA software ? Advanced Visualization and Volume Modeling for volumetric display of the data. The MR data analysis is complicated and cannot be performed without significant training. Dr. Schwab has been the director of the Sleep Imaging Center since 1991 and has an established track record for analyzing such data. The large number of MRI's justifies the establishment of a core devoted to the performing the complicated analysis proposed in Projects 1, and 3. A centralized facility will ensure quality control of the data and cost effectiveness. We will perform MRI's at the University of Pennsylvania and in Iceland. We have already developed a successful collaboration with the Iceland MR team in a large NIH-funded Icelandic study (A Family Linkage Study of Obstructive Sleep Apnea (HL072067)) in which 709 MRI's of the upper airway have been performed. These MRI's have already been analyzed. In addition we have established track record of performing MRI in rodents. We have published two studies examining upper airway soft tissue/craniofacial structures including tongue fat in mice and rats. Thus we have a track record for upper airway imaging in humans and rodents. The Magnetic Resonance Imaging Core will be under the leadership of Dr. Richard Schwab with support staff consisting of senior research radiologist (Dr. Torigian), and three research technicians to perform and validate the image analysis. Development of a central core facility with expertise in upper airway imaging in humans and mice will facilitate the proposed research by standardizing the imaging analysis paradigms, allow the development of new image analysis approaches and ensure quality assurance/reproducibility across the research projects.